OpenRefine

A free, open source power tool for improving your data.

Dealing with messy data doesn't have to be painful. OpenRefine is a powerful tool for working with messy data: cleaning it; transforming it from one format into another; and extending it with web services and external data.

The tool lets you apply transformations over many existing cells in bulk - say, "show me every row where the description field contains "&amp" or "for every row where the contract fee is less than 1, multiply the fee by 1000".

To specify patterns, OpenRefine uses filters and facets. Typically, you create a filter or facet on a particular column, which can then be queried.

OpenRefine is a desktop application in that you download it, install it, and run it on your own computer. However, unlike most other desktop applications, it runs as a small web server.

Formerly supported by Google, the tool is free and open source under the BSD license.

Get started

To help you get acquainted with its functionality, OpenRefine's developers have created a number of tutorial videos as well as documenting more complicated recipes.